Cover window and display apparatus including the same

ABSTRACT

A cover window includes a window substrate having a first hardness and including polyvinylidene fluoride (PVDF), and a hard coating layer on at least one surface of the window substrate and having a second hardness which is greater than that of the window substrate.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. application Ser. No. 17/237,983filed on Apr. 22, 2021, which is based on and claims priority under 35U.S.C. § 119 to Korean Patent Application No. 10-2020-0124642, filed onSep. 25, 2020, in the Korean Intellectual Property Office, thedisclosure of which is incorporated by reference herein in its entirety.

BACKGROUND 1. Field

The present inventive concept relates to a cover window and a displayapparatus including the cover window, and more particularly, to a coverwindow having improved product reliability and a display apparatusincluding the cover window.

2. Description of Related Art

Electronic devices, such as smart phones, monitors, televisions (TVs),notebooks, and digital cameras, include display apparatuses to displayimages. A display apparatus visually displays data and includes adisplay panel that displays an image through a plurality of pixels.

Recently, the usage of display apparatuses has diversified. Also,display apparatuses have become thinner and more lightweight, and thus,the use of display apparatuses has expanded into various applications.

Furthermore, because recent display apparatuses include a touch panel,information may be input from the outside through a user's touch on adisplay screen. Therefore, there are many cases in which a user'sfingers or the like touches the surface of the cover window, and thecover window may affect the sensing sensitivity (or touch sensitivity)of the touch panel.

SUMMARY

One or more embodiments include a cover window having considerablesensing sensitivity while having considerable flexibility, hardness, andscratch resistance, and a display apparatus including the cover window.However, this is merely an example, and the scope of the disclosure isnot limited thereby.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments of the disclosure.

According to one or more embodiments of the present inventive concept, acover window includes a window substrate having a first hardness andincluding polyvinylidene fluoride (PVDF), and a hard coating layer on atleast one surface of the window substrate and having a second hardnesswhich is greater than that of the window substrate.

The window substrate includes a copolymer of a first polymer resin andthe PVDF.

The first polymer resin includes polymethyl methacrylate (PMMA).

A relative permittivity of the window substrate has a value from about 3to about 6.

A thickness of the window substrate has a value from about 100 μm toabout 650 μm.

The hard coating layer includes a first hard coating layer that is on afirst surface of the window substrate and has a thickness less than thatof the window substrate.

The thickness of the first hard coating layer has a value from about 10μm to about 50 μm.

A hardness of the first hard coating layer is greater than that of thewindow substrate, and when the hardness of the first hard coating layeris measured in a pencil hardness, the hardness of the first hard coatinglayer has a value of at least 7H.

The hard coating layer further includes a second hard coating layer on asecond surface opposite to the first surface of the window substrate.

A thickness of the second hard coating layer has a value from about 5 μmto about 20 μm.

The hard coating layer includes polysilsesquioxane or an acrylic polymermaterial.

The sum of a thickness of the window substrate and a thickness of thehard coating layer has a value from about 150 μm to about 700 μm.

According to one or more embodiments of the present inventive concept, adisplay apparatus includes a display panel configured to provide animage, and a cover window on the display panel, wherein the cover windowincludes a window substrate including polyvinylidene fluoride (PVDF),and a hard coating layer on at least one surface of the windowsubstrate.

The window substrate may include a copolymer of polymethyl methacrylate(PMMA) and the PVDF.

The display apparatus further includes an input sensing layer betweenthe display panel and the cover window and including sensing electrodesand trace lines electrically connected to the sensing electrodes, and anadhesive layer between the input sensing layer and the cover window.

A relative permittivity of the adhesive layer is greater than a relativepermittivity of the window substrate.

A thickness of the adhesive layer has a value from about 100 μm to about300 μm.

A relative permittivity of the window substrate has a value from about 3to about 6, and a thickness of the window substrate has a value fromabout 100 μm to about 650 μm.

The hard coating layer has a thickness having a value from about 10 μmto about 50 μm, and has a hardness greater than that of the windowsubstrate.

The sum of a thickness of the window substrate and a thickness of thehard coating layer has a value from about 150 μm to about 700 μm.

According to one or more embodiments of the present inventive concept, adisplay apparatus includes a display panel configured to provide animage, a window substrate disposed on the display panel and comprising acopolymer of a first polymer resin and polyvinylidene fluoride (PVDF), arelative permittivity of the window substrate having a value from about3 to about 6, and a first hard coating layer on the window substrate.The first hard coating layer includes a fluorine-based compound, andwherein the window substrate is disposed between the display panel andthe first hard coating layer.

Other aspects, features and advantages of the disclosure will becomebetter understood through the accompanying drawings, the claims and thedetailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of certainembodiments of the disclosure will be more apparent from the followingdescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a schematic plan view of a display apparatus according to anembodiment of the present inventive concept;

FIG. 2 is a schematic cross-sectional view of a display apparatusaccording to an embodiment of the present inventive concept;

FIG. 3 is a schematic cross-sectional view of a display apparatusaccording to an embodiment of the present inventive concept;

FIG. 4 is an equivalent circuit diagram of a pixel circuit included in adisplay apparatus according to an embodiment of the present inventiveconcept;

FIG. 5 is a schematic plan view of an input sensing layer of a displayapparatus according to an embodiment of the present inventive concept;

FIG. 6 is a cross-sectional view illustrating a stack structure of aninput sensing layer according to an embodiment of the present inventiveconcept;

FIGS. 7A and 7B are respectively plan views of a first conductive layerand a second conductive layer in an input sensing layer according to anembodiment of the present inventive concept;

FIG. 8 is a schematic cross-sectional view of a cover window and anadhesive layer of a display apparatus according to an embodiment of thepresent inventive concept; and

FIG. 9 is a schematic cross-sectional view of a cover window and anadhesive layer of a display apparatus according to another embodiment ofthe present inventive concept.

DETAILED DESCRIPTION

As the present description allows for various changes and numerousembodiments, certain embodiments will be illustrated in the drawings anddescribed in detail in the written description. Effects and features ofthe disclosure, and methods of achieving them will be clarified withreference to embodiments described below in detail with reference to thedrawings. However, the disclosure is not limited to the followingembodiments and may be embodied in various forms.

The embodiments of the disclosure will be described below in more detailwith reference to the accompanying drawings. Those elements that are thesame or are in correspondence with each other are rendered the samereference numeral regardless of the figure number, and redundantexplanations are omitted.

It will be understood that although the terms “first,” “second,” etc.may be used herein to describe various elements, these elements shouldnot be limited by these terms. These terms are only used to distinguishone element from another.

The singular forms “a,” “an,” and “the” as used herein are intended toinclude the plural forms as well unless the context clearly indicatesotherwise.

It will be further understood that the terms “comprises” and/or“comprising” used herein specify the presence of stated features orelements, but do not preclude the presence or addition of one or moreother features or elements.

It will be further understood that, when a layer, region, or element isreferred to as being “on” another layer, region, or element, it can bedirectly or indirectly on the other layer, region, or element. Forexample, intervening layers, regions, or elements may be present.

Sizes of elements in the drawings may be exaggerated or reduced forconvenience of explanation. For example, because sizes and thicknessesof elements in the drawings are arbitrarily illustrated for convenienceof explanation, the disclosure is not limited thereto.

When a certain embodiment may be implemented differently, a specificprocess order may be performed differently from the described order. Forexample, two consecutively described processes may be performedsubstantially at the same time or performed in an order opposite to thedescribed order.

In this specification, the expression “A and/or B” indicates only A,only B, or both A and B. Throughout the disclosure, the expression “atleast one of A and B” indicates only A, only B, or both A and B.

It will be further understood that, when layers, regions, or componentsare referred to as being connected to each other, they may be directlyconnected to each other or indirectly connected to each other withintervening layers, regions, or components therebetween. For example,when layers, regions, or components are referred to as beingelectrically connected to each other, they may be directly electricallyconnected to each other or indirectly electrically connected to eachother with intervening layers, regions, or components therebetween.

The x-axis, the y-axis, and the z-axis are not limited to three axes ofthe rectangular coordinate system and may be interpreted in a broadersense. For example, the x-axis, the y-axis, and the z-axis may beperpendicular to one another or may represent different directions thatare not perpendicular to one another.

FIG. 1 is a schematic plan view of a display apparatus 1 according to anembodiment.

Referring to FIG. 1 , the display apparatus 1 may include a display areaDA and a peripheral area PA outside the display area DA. The displayapparatus 1 may display an image through an array of a plurality ofpixels PX that are two-dimensionally arranged in the display area DA.

The peripheral area PA is an area that does not display an image, andmay completely or partially surround the display area DA. A driver orthe like, which provides an electric signal or power to a pixel circuitcorresponding to each of the pixels PX, may be arranged in theperipheral area PA. A pad, which is an area to which an electronicdevice or a printed circuit board may be electrically connected, may bearranged in the peripheral area PA.

The display apparatus 1 includes an organic light-emitting diode (OLED)as a light-emitting element, but the display apparatus 1 of thedisclosure is not limited thereto. According to another embodiment, thedisplay apparatus 1 may include a light-emitting display apparatusincluding an inorganic light-emitting diode, that is, an inorganiclight-emitting display. The inorganic light-emitting diode may include aPN junction diode including inorganic semiconductor-based materials.When a voltage is applied to the PN junction diode in a forwarddirection, holes and electrons may be injected and recombined togenerate energy. The PN junction diode may convert the generated energyinto light energy to emit light of a certain color. The inorganiclight-emitting diode may have a width of several micrometers to severalhundred micrometers. In some embodiments, the inorganic light-emittingdiode may be referred to as a micro light-emitting diode (LED).According to another embodiment, the display apparatus 1 may include aquantum dot light-emitting display.

The display apparatus 1 may be used as display screens for variousproducts such as not only portable electronic devices, such as mobilephones, smart phones, tablet personal computers (PCs), mobilecommunication terminals, electronic notebooks, e-books, portablemultimedia players (PMPs), navigations, and ultra mobile PCs (UMPCs),and but also televisions (TVs), laptops, monitors, billboards, andinternet of things (IOT) devices. The display apparatus 1 according toan embodiment may also be used in wearable devices, such as smartwatches, watch phones, glasses-type displays, or head mounted displays(HMDs). The display apparatus 1 according to an embodiment may also beused as dashboards of automobiles, center information displays (CIDs) ofthe center fascia or dashboards of automobiles, room mirror displaysthat replace the side mirrors of automobiles, and display screensarranged on the rear sides of front seats to serve as entertainmentdevices for back seat passengers of automobiles.

FIG. 2 is a schematic cross-sectional view of a display apparatus 1according to an embodiment.

Referring to FIG. 2 , the display apparatus 1 may include a displaypanel 10, and an input sensing layer 40 and an optical functional layer50, which are on the display panel 10. The display panel 10, the inputsensing layer 40, and the optical functional layer 50 may be covered bya cover window 70.

The display panel 10 may include a plurality of light-emitting elementsand a plurality of pixel circuits electrically connected to thelight-emitting elements, and may display an image through light emittedfrom the light-emitting elements.

The input sensing layer 40 may obtain coordinate information accordingto an external input, for example, a touch event. The input sensinglayer 40 may include sensing electrodes (or touch electrodes) and tracelines electrically connected to the sensing electrodes. The inputsensing layer 40 may be on the display panel 10. The input sensing layer40 may sense an external input using a mutual cap method or a self capmethod.

The input sensing layer 40 may be on the display panel 10.Alternatively, the input sensing layer 40 may be formed separately andthen bonded through an adhesive member (not illustrated). As theadhesive member, any general members known in the art may be usedwithout limitation. The adhesive member may include an optical clearadhesive (OCA). According to an embodiment, as illustrated in FIG. 2 ,the input sensing layer 40 may be on the display panel 10. The adhesivemember is not between the input sensing layer 40 and the display panel10.

The optical functional layer 50 may include an anti-reflective layer.The anti-reflective layer may reduce reflectance of light (externallight) incident from the outside toward the display panel 10 through thecover window 70. The anti-reflective layer may include a retarder and apolarizer. The retarder may be a film-type retarder or a liquid crystalcoating-type retarder. In an embodiment, the retarder is a λ/2 retarderand/or a λ/4 retarder. The polarizer may be a film-type polarizer or aliquid crystal coating-type polarizer. The film-type polarizer mayinclude a stretched synthetic resin film, and the liquid crystalcoating-type polarizer may include liquid crystals arranged in a certainarray. The retarder and the polarizer may further include a protectivefilm.

According to another embodiment, the anti-reflective layer may include astructure of a black matrix and color filters. The color filters may bearranged to pass through corresponding colors of light emitted from eachpixel of the display panel 10. According to another embodiment, theanti-reflective layer may include a destructive interference structure.The destructive interference structure may include a first reflectivelayer and a second reflective layer, which are on different layers fromeach other. First reflected light and second reflected light, which arerespectively reflected from the first reflective layer and the secondreflective layer, may destructively interfere with each other. Thus, thereflectance of external light is reduced.

The optical functional layer 50 may include a lens layer. The lens layermay improve the light emission efficiency of light emitted from thedisplay panel 10, or may reduce color deviation. The lens layer mayinclude a layer having a concave or convex lens shape, and/or mayinclude a plurality of layers having different refractive indices fromeach other. The optical functional layer 50 may include either or bothof the anti-reflective layer and the lens layer described above.

An adhesive member (not illustrated) may be between the input sensinglayer 40 and the optical functional layer 50. As the adhesive member,any general members known in the art may be used without limitation. Theadhesive member may include an OCA.

The cover window 70 may have a high transmittance sufficient to transmitlight emitted from the display panel 10, and may have a small thicknessto minimize the weight of the display apparatus 1. To protect thedisplay panel 10 from external impact, the cover window 70 may havestrong strength and hardness and may have high impact resistance andscratch resistance.

An adhesive layer 60 may be between the input sensing layer 40 and thecover window 70 and between the optical functional layer 50 and thecover window 70. The cover window 70 may be bonded to an underlyingelement, for example, the optical functional layer 50, through theadhesive layer 60. According to an embodiment, the adhesive layer 60 mayinclude an OCA.

FIG. 3 is a schematic cross-sectional view of a display apparatus 1according to an embodiment, taken along line III-III′ of FIG. 1 . Thesame reference numerals denote the same or corresponding elements amongthe elements described above with reference to FIG. 2 , and redundantdescriptions thereof are omitted.

Referring to FIG. 3 , the display apparatus 1 may include a displaypanel 10, and the display panel 10 may include a stack structure of asubstrate 100, a pixel circuit layer PCL, a display element layer DEL,and an encapsulation layer 300.

The substrate 100 may have a multilayer structure including an inorganiclayer and a base layer including a polymer resin. For example, thesubstrate 100 may include barrier layers of an inorganic insulatinglayer and a base layer including a polymer resin. For example, thesubstrate 100 may include a first base layer 101, a first barrier layer102, a second base layer 103, and a second barrier layer 104, which aresequentially stacked on each other. Each of the first base layer 101 andthe second base layer 103 may include polyimide (PI), polyethersulfone(PES), polyarylate, polyetherimide (PEI), polyethylene naphthalate(PEN), polyethylene terephthalate (PET), polyphenylene sulfide (PPS),polycarbonate (PC), cellulose triacetate (TAC), and/or cellulose acetatepropionate (CAP). Each of the first barrier layer 102 and the secondbarrier layer 104 may include an inorganic insulating material such assilicon oxide, silicon oxynitride, and/or silicon nitride. The substrate100 may be flexible.

The pixel circuit layer PCL is on the substrate 100. FIG. 3 illustratesthat the pixel circuit layer PCL includes a thin-film transistor TFT, abuffer layer 111, a first gate insulating layer 112, a second gateinsulating layer 113, an interlayer insulating layer 114, a firstplanarization insulating layer 115, and a second planarizationinsulating layer 116, which are below and/or above elements of thethin-film transistor TFT.

The buffer layer 111 may reduce or prevent infiltration of a foreignmaterial, moisture, or ambient air from below the substrate 100, and mayprovide a flat surface on the substrate 100. The buffer layer 111 mayinclude an inorganic insulating material such as silicon oxide, siliconoxynitride, or silicon nitride, and may have a single layer structure ora multilayer structure including the above-described material.

The thin-film transistor TFT on the buffer layer 111 may include asemiconductor layer Act, and the semiconductor layer Act may includepolysilicon. Alternatively, the semiconductor layer Act may includeamorphous silicon, an oxide semiconductor, or an organic semiconductor.The semiconductor layer Act may include a channel region C, and a drainregion D and a source region S on opposite sides of the channel regionC. A gate electrode GE may overlap the channel region C.

The gate electrode GE may include a low resistance metal material. Thegate electrode GE may include a conductive material including molybdenum(Mo), aluminum (Al), copper (Cu), titanium (Ti), and the like, and mayinclude a single layer or multiple layers including the above-describedmaterial.

The first gate insulating layer 112 between the semiconductor layer Actand the gate electrode GE may include an inorganic insulating materialsuch as silicon oxide (SiO₂), silicon nitride (SiN_(x)), siliconoxynitride (SiON), aluminum oxide (Al₂O₃), titanium oxide (TiO₂),tantalum oxide (Ta₂O₅), hafnium oxide (HfO₂), or zinc oxide (ZnO).

The second gate insulating layer 113 may be arranged to cover the gateelectrode GE. Similar to the first gate insulating layer 112, the secondgate insulating layer 113 may include an inorganic insulating materialsuch as silicon oxide (SiO₂), silicon nitride (SiN_(x)), siliconoxynitride (SiON), aluminum oxide (Al₂O₃), titanium oxide (TiO₂),tantalum oxide (Ta₂O₅), hafnium oxide (HfO₂), or zinc oxide (ZnO).

An upper electrode Cst2 of a storage capacitor Cst may be on the secondgate insulating layer 113. The upper electrode Cst2 may overlap the gateelectrode GE therebelow. The gate electrode GE and the upper electrodeCst2 overlapping each other with the second gate insulating layer 113therebetween may form the storage capacitor Cst. The gate electrode GEmay function as a lower electrode Cst1 of the storage capacitor Cst.

As such, the storage capacitor Cst and the thin-film transistor TFT mayoverlap each other. According to some embodiments, the storage capacitorCst does not overlap the thin-film transistor TFT.

The upper electrode Cst2 may include aluminum (Al), platinum (Pt),palladium (Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni),neodymium (Nd), iridium (Ir), chromium (Cr), calcium (Ca), molybdenum(Mo), titanium (Ti), tungsten (W), and/or copper (Cu), and may include asingle layer or multiple layers including the above-described material.

The interlayer insulating layer 114 may cover the upper electrode Cst2.The interlayer insulating layer 114 may include silicon oxide (SiO₂),silicon nitride (SiN_(x)), silicon oxynitride (SiON), aluminum oxide(Al₂O₃), titanium oxide (TiO₂), tantalum oxide (Ta₂O₅), hafnium oxide(HfO₂), or zinc oxide (ZnO). The interlayer insulating layer 114 mayinclude a single layer or multiple layers including the above-describedinorganic insulating material.

A drain electrode DE and a source electrode SE may be on the interlayerinsulating layer 114. The drain electrode DE and the source electrode SEmay be respectively connected to the drain region D and the sourceregion S through contact holes formed in the insulating layerstherebelow. Each of the drain electrode DE and the source electrode SEmay include a material having good conductivity. Each of the drainelectrode DE and the source electrode SE may include a conductivematerial including molybdenum (Mo), aluminum (Al), copper (Cu), titanium(Ti), and the like, and may include a single layer or multiple layersincluding the above-described material. According to an embodiment, thedrain electrode DE and the source electrode SE may have a multilayerstructure of Ti/Al/Ti.

The first planarization insulating layer 115 may cover the drainelectrode DE and the source electrode SE. The first planarizationinsulating layer 115 may include an organic insulating material such asa polymer (e.g., polymethyl methacrylate (PMMA) or polystyrene (PS)), apolymer derivative having a phenol-based group, an acrylic polymer, animide-based polymer, an aryl ether-based polymer, an amide-basedpolymer, a fluorine-based polymer, a p-xylene-based polymer, a vinylalcohol-based polymer, and a blend thereof.

The second planarization insulating layer 116 may be on the firstplanarization insulating layer 115. The second planarization insulatinglayer 116 may include the same material as that of the firstplanarization insulating layer 115, and may include an organicinsulating material such as a polymer (e.g., PMMA or PS), a polymerderivative having a phenol-based group, an acrylic polymer, animide-based polymer, an aryl ether-based polymer, an amide-basedpolymer, a fluorine-based polymer, a p-xylene-based polymer, a vinylalcohol-based polymer, and a blend thereof.

The display element layer DEL may be on the pixel circuit layer PCLhaving the above-described structure. The display element layer DEL mayinclude an organic light-emitting diode OLED as a display element (i.e.,a light-emitting element), and the organic light-emitting diode OLED mayinclude a stack structure of a pixel electrode 210, a middle layer 220,and a common electrode 230. For example, the organic light-emittingdiode OLED may emit red light, green light, or blue light, or may emitred light, green light, blue light, or white light. The organiclight-emitting diode OLED may emit light through an emission area, andthe emission area may be defined as a pixel PX.

The pixel electrode 210 of the organic light-emitting diode OLED may beelectrically connected to the thin-film transistor TFT through contactholes formed in the second planarization insulating layer 116 and thefirst planarization insulating layer 115. A contact metal CM may bearranged on the first planarization insulating layer 115 to facilitatethe connection between the pixel electrode 210 and the thin-filmtransistor TFT.

The pixel electrode 210 may include conductive oxide such as indium tinoxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium oxide(In₂O₃), indium gallium oxide (IGO), or aluminum zinc oxide (AZO).According to another embodiment, the pixel electrode 210 may include areflective layer including silver (Ag), magnesium (Mg), aluminum (Al),platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd),Iridium (Ir), chromium (Cr), or any compound thereof. According toanother embodiment, the pixel electrode 210 may further include a layerincluding ITO, IZO, ZnO, or In₂O₃ above and/or below the reflectivelayer.

A pixel defining layer 117 having an opening 1170P exposing the centralportion of the pixel electrode 210 is on the pixel electrode 210. Thepixel defining layer 117 may include an organic insulating materialand/or an inorganic insulating material. The opening 1170P may define anemission area through which the organic light-emitting diode OLED emitslight. For example, the size and/or width of the opening 1170P maycorrespond to the size and/or width of the emission area. Therefore, thesize and/or width of the pixel PX may depend on the size and/or width ofthe opening 1170P of the corresponding pixel defining layer 117.

The middle layer 220 may include an emission layer 222 formed on thepixel electrode 210. The emission layer 222 may include a high molecularweight organic material or a low molecular weight organic material thatemits light of a certain color. Alternatively, the emission layer 222may include an inorganic emission material or quantum dots.

According to an embodiment, the middle layer 220 may include a firstfunctional layer 221 and a second functional layer 223 below and abovethe emission layer 222, respectively. The first functional layer 221 mayinclude, for example, a hole transport layer (HTL), or may include anHTL and a hole injection layer (HIL). The second functional layer 223may be on the emission layer 222, and may include an electron transportlayer (ETL) and/or an electron injection layer (EIL). Like a commonelectrode 230 to be described later, the first functional layer 221and/or the second functional layer 223 may be a common layer entirelycovering the substrate 100.

The common electrode 230 may be on the pixel electrode 210 and mayoverlap the pixel electrode 210. The common electrode 230 may include aconductive material having a low work function. For example, the commonelectrode 230 may include a transparent or semi-transparent layerincluding silver (Ag), magnesium (Mg), aluminum (Al), platinum (Pt),palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir),chromium (Cr), lithium (Li), calcium (Ca), or any alloy thereof.Alternatively, the common electrode 230 may further include a layer suchas ITO, IZO, ZnO, or In₂O₃ on the transparent layer or thesemi-transparent layer including the above-described material. Thecommon electrode 230 may be integrally formed to entirely cover thesubstrate 100.

The encapsulation layer 300 may be on the display element layer DEL andmay cover the display element layer DEL. The encapsulation layer 300includes at least one inorganic encapsulation layer and at least oneorganic encapsulation layer. As an embodiment, FIG. 3 illustrates thatthe encapsulation layer 300 includes a first inorganic encapsulationlayer 310, an organic encapsulation layer 320, and a second inorganicencapsulation layer 330, which are sequentially stacked on each other.

Each of the first inorganic encapsulation layer 310 and the secondinorganic encapsulation layer 330 may include one or more inorganicmaterials selected from aluminum oxide, titanium oxide, tantalum oxide,hafnium oxide, zinc oxide, silicon oxide, silicon nitride, and siliconoxynitride. The organic encapsulation layer 320 may include apolymer-based material. The polymer-based material may include anacrylic resin, an epoxy-based resin, polyimide, polyethylene, and thelike. According to an embodiment, the organic encapsulation layer 320may include acrylate. The organic encapsulation layer 320 may be formedby curing a monomer or applying a polymer. The organic encapsulationlayer 320 may be transparent.

FIG. 4 is an equivalent circuit diagram of a pixel circuit PC includedin a display apparatus, according to an embodiment.

Referring to FIG. 4 , the pixel circuit PC may include a plurality ofthin-film transistors and a storage capacitor, and may be electricallyconnected to an organic light-emitting diode OLED. According to anembodiment, the pixel circuit PC may include a driving thin-filmtransistor T1, a switching thin-film transistor T2, and a storagecapacitor Cst.

The switching thin-film transistor T2 may be connected to a scan line SLand a data line DL and may transmit a data voltage or a data voltageinput from the data line DL to the driving thin-film transistor T1 basedon a scan signal or a switching voltage input from the scan line SL. Thestorage capacitor Cst may be connected to the switching thin-filmtransistor T2 and a driving voltage line PL and may store a voltagecorresponding to a difference between a voltage received from theswitching thin-film transistor T2 and a first power supply voltage ELVDDsupplied to the driving voltage line PL.

The driving thin-film transistor T1 may be connected to the drivingvoltage line PL and the storage capacitor Cst and may control a drivingcurrent flowing from the driving voltage line PL to the organiclight-emitting diode OLED in response to a voltage value stored in thestorage capacitor Cst. A common electrode (e.g., a cathode) of theorganic light-emitting diode OLED may receive a second power supplyvoltage ELVSS. The organic light-emitting diode OLED may emit lighthaving a certain luminance according to the driving current.

Although a case in which the pixel circuit PC includes two thin-filmtransistors and one storage capacitor has been described, the disclosureis not limited thereto. For example, the pixel circuit PC may includethree or more thin-film transistors and/or two or more storagecapacitors. According to an embodiment, the pixel circuit PC may includeseven thin-film transistors and one storage capacitor. The number ofthin-film transistors and the number of storage capacitors may bevariously changed according to the design of the pixel circuit PC.However, for convenience of description, a case in which the pixelcircuit PC includes two thin-film transistors and one storage capacitorwill be described.

FIG. 5 is a schematic plan view of an input sensing layer 40 of adisplay apparatus, according to an embodiment.

Referring to FIG. 5 , the input sensing layer 40 may include firstsensing electrodes 410, first trace lines 415-1 to 415-4 connected tothe first sensing electrodes 410, second sensing electrodes 420, andsecond trace lines 425-1 to 425-5 connected to the second sensingelectrodes 420. The first sensing electrodes 410 and the second sensingelectrodes 420 may be arranged in a display area DA, and the first tracelines 415-1 to 415-4 and the second trace lines 425-1 to 425-5 may bearranged in a peripheral area PA.

The first sensing electrodes 410 may be arranged in the ±y direction,and the second sensing electrodes 420 may be arranged in the ±xdirection intersecting with the ±y direction. The first sensingelectrodes 410 arranged in the ±y direction may be connected to eachother by first connection electrodes 411 between the adjacent firstsensing electrodes 410 to form first sensing lines 410C1 to 410C4,respectively. The second sensing electrodes 420 arranged in the ±xdirection may be connected to each other by second connection electrodes421 between the adjacent second sensing electrodes 420 to form secondsensing lines 420R1 to 420R5, respectively. The first sensing lines410C1 to 410C4 and the second sensing lines 420R1 to 420R5 may intersectwith each other. For example, the first sensing lines 410C1 to 410C4 andthe second sensing lines 420R1 to 420R5 may perpendicularly intersectwith each other.

The first sensing lines 410C1 to 410C4 may be connected to pads of asensing signal pad part 440 through the first trace lines 415-1 to 415-4formed in the peripheral area PA. For example, the first trace lines415-1 to 415-4 may have a double routing structure. The first tracelines 415-1 to 415-4 may be respectively connected to the upper andlower sides of the first sensing lines 410C1 to 410C4. The first tracelines 415-1 to 415-4 respectively connected to the upper and lower sidesof the first sensing lines 410C1 to 410C4 may be connected to thecorresponding pads.

The second sensing lines 420R1 to 420R5 may be connected to the pads ofthe sensing signal pad part 440 through the second trace lines 425-1 to425-5 formed in the peripheral area PA. For example, the second tracelines 425-1 to 425-5 may be connected to the corresponding pads.

FIG. 5 illustrates the double routing structure in which the first tracelines 415-1 to 415-4 are connected to both the upper sides and the lowersides of the first sensing lines 410C1 to 410C4, respectively. Thedouble routing structure may improve sensing sensitivity (or touchsensitivity). However, the disclosure is not limited thereto. Accordingto another embodiment, the first trace lines 415-1 to 415-4 may have asingle routing structure. The first trace lines 415-1 to 415-4 may beconnected to the upper sides and the lower sides of the first sensinglines 410C1 to 410C4, respectively.

FIG. 6 is a cross-sectional view illustrating a stack structure of aninput sensing layer 40 according to an embodiment.

Referring to FIG. 6 , the input sensing layer 40 may include a firstconductive layer CML1 and a second conductive layer CML2. A firstinsulating layer 43 may be between the first conductive layer CML1 andthe second conductive layer CML2, and a second insulating layer 45 maybe on the second conductive layer CML2. Each of the first sensingelectrodes (see 410 of FIG. 5 ), the first connection electrodes (see411 of FIG. 5 ), the second sensing electrodes (see 420 of FIG. 5 ), andthe second connection electrodes (see 421 of FIG. 5 ) may be included ineither the first conductive layer CML1 or the second conductive layerCML2.

The first and second conductive layers CML1 and CML2 may include a metallayer or a transparent conductive layer. The metal layer may includemolybdenum (Mo), mendelevium (Mb), silver (Ag), titanium (Ti), copper(Cu), aluminum (Al), and any alloy thereof. The transparent conductivelayer may include a transparent conductive oxide such as ITO, IZO, ZnO,and indium tin zinc oxide (ITZO). The transparent conductive layer mayinclude a conductive polymer such as poly(3,4-ethylenedioxythiophene)(PEDOT), metal nanowires, or graphene.

The first and second conductive layers CML1 and CML2 may include asingle or multiple layers. The single-layered first and secondconductive layers CML1 and CML2 may include a metal layer or atransparent conductive layer, and materials of the metal layer and thetransparent conductive layer are the same as described above. Either thefirst conductive layer CML1 or the second conductive layer CML2 mayinclude a single metal layer. The single metal layer may include amolybdenum layer or an alloy layer of MoMd. Either the first conductivelayer CML1 or the second conductive layer CML2 may include amultilayered metal layer. The multilayered metal layer may include, forexample, three layers of a titanium layer/aluminum layer/titanium layer,or may include two layers of a molybdenum layer/mendelevium layer.Alternatively, the multilayered metal layer may include a metal layerand a transparent conductive layer. The first and second conductivelayers CML1 and CML2 may have different stack structures or may have thesame stack structure. For example, the first conductive layer CML1 mayinclude a metal layer, and the second conductive layer CML2 may includea transparent conductive layer. Alternatively, the first and secondconductive layers CML1 and CML2 may include the same metal layer.

The materials of the first and second conductive layers CML1 and CML2,and the arrangement of the sensing electrodes provided in the first andsecond conductive layers CML1 and CML2 may be formed to secure sensingsensitivity. An RC delay may affect the sensing sensitivity. Because thesensing electrodes including the metal layer have a low resistancecompared with the transparent conductive layers, an RC delay of thesensing electrodes with the metal layer may be reduced. Therefore, thecharging time of the capacitor defined between the sensing electrodesmay be reduced. The sensing electrodes including the transparentconductive layers are not visible to a user compared with the metallayers, and the input area may increase, thereby increasing thecapacitance.

Each of the first and second insulating layers 43 and 45 may include aninorganic insulating material or/and an organic insulating material. Theinorganic insulating material may include silicon oxide, siliconnitride, or silicon oxynitride, and the organic insulating material mayinclude a high molecular weight organic material.

Some of the first and second sensing electrodes 410 and 420, and thefirst and second connection electrodes 411 and 421 described above withreference to FIG. 5 may be located at the first conductive layer CML1,and the others thereof may be located at the second conductive layerCML2. According to an embodiment, the first conductive layer CML1 mayinclude the first connection electrodes 411, and the second conductivelayer CML2 may include the first and second sensing electrodes 410 and420, and the second connection electrodes 421. According to anotherembodiment, the first conductive layer CML1 may include the first andsecond sensing electrodes 410 and 420, and the second connectionelectrodes 421, and the second conductive layer CML2 may include thefirst connection electrodes 411. According to another embodiment, thefirst conductive layer CML1 may include the first sensing electrodes 410and the first connection electrodes 411, and the second conductive layerCML2 may include the second sensing electrodes 420 and the secondconnection electrodes 421. The first sensing electrodes 410 and thefirst connection electrodes 411 are provided at the same layer andintegrally connected to each other, and the second sensing electrodes420 and the second connection electrodes 421 are also at the same layer.Therefore, no contact holes may be provided in the insulating layerbetween the first conductive layer CML1 and the second conductive layerCML2.

FIG. 6 illustrates that the input sensing layer 40 includes the firstconductive layer CML1, the first insulating layer 43, the secondconductive layer CML2, and the second insulating layer 45, but inanother embodiment, a layer including an inorganic insulating material,or an organic insulating material may be further arranged under thefirst conductive layer CML1.

FIGS. 7A and 7B are respectively plan views of the first conductivelayer and the second conductive layer in the input sensing layer,according to an embodiment.

Referring to FIGS. 7A and 7B, the first and second sensing electrodes410 and 420 and the first and second connection electrodes 411 and 421may have a mesh (or grid) shape. When the first and second sensingelectrodes 410 and 420 include a metal layer, the first and secondsensing electrodes 410 and 420 may have a mesh shape as illustrated inFIGS. 7A and 7B to prevent the first and second sensing electrodes 410and 420 from being visible to the user and/or to transmit light emittedfrom each pixel PX.

As illustrated in the enlarged views of FIGS. 7A and 7B, the first andsecond sensing electrodes 410 and 420 may include mesh-shaped metallayers including holes 410H and 420H, respectively. Similarly, the firstand second connection electrodes 411 and 421 may also includemesh-shaped metal layers including holes 411H and 421H, respectively.The holes 410H, 420H, 411H, and 421H may be arranged to overlap thepixels PX.

As illustrated in FIG. 7A, the first conductive layer CML1 may includethe first connection electrode 411. The first connection electrode 411may be electrically connected to the first sensing electrodes 410 formedat the second conductive layer CML2 which is a different layer from thefirst conductive layer CML1. The first connection electrode 411electrically connecting the adjacent first sensing electrodes 410 toeach other may be connected to the first sensing electrodes 410 througha contact hole CNT formed in the first insulating layer (see 43 of FIG.6 ).

As illustrated in FIG. 7B, the second conductive layer CML2 may includethe first sensing electrode 410, the second sensing electrode 420, andthe second connection electrode 421. The second sensing electrodes 420may be connected to each other by the second connection electrodes 421formed at the same layer as the second sensing electrodes 420. Forexample, the second sensing electrodes 420 include the same material asthat of the second connection electrodes 421 and may be integrallyformed with each other. The first sensing electrodes 410 may beelectrically connected to each other by the first connection electrodes411 formed at a different layer from the first sensing electrodes 410.The first sensing electrodes 410 may be connected to the firstconnection electrodes 411 through the contact hole CNT formed in thefirst insulating layer 43.

FIG. 8 is a schematic cross-sectional view of a cover window and anadhesive layer of a display apparatus according to an embodiment.

Referring to FIG. 8 , a cover window 70 may include a window substrateWS and a hard coating layer HC on at least one surface of the windowsubstrate WS.

According to an embodiment, the window substrate WS may include apolymer resin. For example, the window substrate WS may include at leastone material selected from polyethersulfone, polyacrylate, polyetherimide, polyethylene naphthalate, polyethylene terephthalate,polyphenylene sulfide, polyarylate, polyimide, polycarbonate (PC),cellulose triacetate, cellulose acetate propionate,polyaryleneethersulfones, benzocyclobutene, hexamethyldisiloxane, andpolymethyl methacrylate (PMMA). According to an embodiment, the windowsubstrate WS may include a copolymer of a first polymer resin and asecond polymer resin.

As a comparative example, when the window substrate includes a glassmaterial, it may be difficult to secure flexibility and there may be ahigh possibility of cracking or breaking due to external impact.However, according to an embodiment, because the window substrate WSincludes a polymer resin, flexibility may be secured and the possibilityof cracking or breaking due to external impact may be minimized.

When the window substrate WS includes a specific polymer resin, thesensing sensitivity (or touch sensitivity) of the input sensing layer(see 40 of FIG. 2 ) of the display apparatus (see 1 of FIG. 2 ) maydeteriorate, as compared with a case in which the window substrateincludes a glass material. For example, when the window substrate WSincludes PMMA and/or PC, the sensing sensitivity of the displayapparatus 1 may deteriorate, as compared to a case where the windowsubstrate includes a glass material. This is because the relativepermittivity of the window substrate WS including PMMA and/or PC is lessthan the relative permittivity of the window substrate including glass.

The relative permittivity of the window substrate WS, more specifically,the relative permittivity of the cover window 70 may affect the sensingsensitivity of the input sensing layer 40 of the display apparatus 1.The relative permittivity is a value represented by a relative ratio ofthe permittivity of a material layer to the permittivity of the vacuum,and the permittivity is a physical property indicating a size ofpolarization made by a dielectric in response to an external electricfield.

For example, the input sensing layer 40 of the display apparatus 1 mayinclude a touch screen panel (TSP) of a capacitive scheme. Thecapacitive scheme receives an external input by sensing a magnitude of acapacitance change of the input sensing layer 40 and a position of theinput sensing layer 40. For example, a constant electric field may beformed by flowing a certain amount of current through the sensingelectrodes (see 410 and 420 of FIG. 5 ) of the input sensing layer 40.Because a user's body is an electrical charge conductor, a change in theelectric field occurs in the corresponding portion of the input sensinglayer 40 at the moment the user touches the touch screen. Thecapacitance changes due to the change in the electric field, and theexternal input may be received by sensing such a change. Therefore, asthe magnitude of the capacitance change increases, the sensingsensitivity of the input sensing layer 40 may be improved.

The cover window 70 may be on the input sensing layer 40 and may be onthe outermost side of the product so that the user touches the coverwindow 70. When the user touches the cover window 70, the electric fieldchanges in a corresponding portion of the input sensing layer 40 throughthe cover window 70, and the capacitance changes. Therefore, as therelative permittivity of the cover window 70 increases with respect tothe same input (i.e., the same touch event), the capacitance change ofthe input sensing layer 40 may increase, and thus, the sensingsensitivity may be improved.

According to an embodiment, the window substrate WS may includepolyvinylidene fluoride (PVDF). The relative permittivity of PVDF mayhave a value from about 7 to about 7.5. The window substrate WS includesor is PVDF having a high relative permittivity, so that the relativepermittivity of the cover window 70 may be improved.

According to an embodiment, the window substrate WS may include acopolymer of a first polymer resin and PVDF. For example, the firstpolymer resin may be PMMA. The relative permittivity of the windowsubstrate WS may be determined depending on a ratio of the first polymerresin and PVDF. The relative permittivity of the window substrate WS mayhave a value from about 3 to about 7, or from about 3 to about 6.Specifically, the relative permittivity of the window substrate WS maybe about 5.

As a comparative example, when the window substrate includes a polymerresin other than PVDF, for example, PMMA and/or PC, the relativepermittivity of the window substrate WS may have a value from about 2.5to about 3. However, according to an embodiment, because the windowsubstrate WS includes PVDF having a high relative permittivity, thewindow substrate WS may have a higher relative permittivity than that ofthe window substrate of the comparative example. Thus, the sensingsensitivity of the display apparatus 1 may be improved.

According to an embodiment, a hard coating layer HC may be on a firstsurface S1 of the window substrate WS. For example, the hard coatinglayer HC may be on the first surface S1 of the window substrate WS. Thefirst surface S1 of the window substrate WS may be the outer surface ofthe window substrate WS facing the user. According to an embodiment, thehard coating layer HC may include polysilsesquioxane or an acrylicpolymer material.

According to an embodiment, the hardness of the hard coating layer HCmay be greater than the hardness of the window substrate WS. Therefore,the overall hardness of the cover window 70 may be improved, and scratchresistance may be improved. For example, the pencil hardness of thecover window 70 may be about 7H. Also, because the hard coating layer HCincludes a fluorine-based compound, the hard coating layer HC may haveanti-fingerprint (AF) characteristics. For example, the hard coatinglayer HC includes perfluoropolyether (PEPE). In an embodiment, thepencil hardness of the hard coating layer HC may be at least about 7H orgreater than that (e.g., 8H or 9H).

According to an embodiment, a thickness t1 of the window substrate WSmay have a value from about 100 μm to about 650 μm, from about 100 μm toabout 550 μm, from about 100 μm to about 450 μm, or from about 100 μm toabout 350 μm.

A thickness t2 of the hard coating layer HC may be less than thethickness t1 of the window substrate WS. For example, the thickness t2of the hard coating layer HC may have a value from about 10 μm to about50 μm. When the thickness t2 of the hard coating layer HC is less thanabout 10 μm, it is difficult to secure sufficient hardness, and when thethickness t2 is greater than about 50 μm, the possibility of crackingdue to external impact may increase.

A thickness to of the cover window 70, that is, the sum of the thicknesst1 of the window substrate WS and the thickness t2 of the hard coatinglayer HC, may have a value from about 150 μm to about 700 μm, from about150 μm to about 600 μm, from about 150 μm to about 500 μm, from about150 μm to about 400 μm, or from about 150 μm to about 300 μm.

Similar to the relationship between the relative permittivity and thesensing sensitivity described above, as the total thickness of the coverwindow 70 decreases with respect to the same input (i.e., the same touchevent), the capacitance change of the input sensing layer 40 mayincrease, and thus, the sensing sensitivity may be improved.

Table 1 below shows a magnitude of a capacitance change according to athickness of a cover window with respect to a cover window ofComparative Example 1, a cover window of Comparative Example 2, and acover window of Example 1.

TABLE 1 Thickness [μm] 300 400 500 600 700 800 900 1000 Comparative 121117 111 106 101 96 91 87 Example 1 Comparative 72 65 59 55 51 47 44 41Example 2 Example 1 101 94 89 83 79 74 70 66

The cover window of Comparative Example 1 includes a window substratehaving a relative permittivity of about 7.2 and including a glassmaterial. The cover window of Comparative Example 2 includes a windowsubstrate having a relative permittivity of about 2.8 and including PMMAand PC. The cover window 70 of Example 1 includes a window substratehaving a relative permittivity of about 5 and including a copolymer ofPMMA and PVDF. Comparative Example 1, Comparative Example 2, and Example1 all include a hard coating layer HC having a thickness of about 50 μm.The unit of the thickness of the cover window is micrometer (μm), andthe unit of the magnitude of the capacitance change is femto farad (fF).

Referring to Table 1, it may be confirmed that the cover window 70 ofExample 1 generally has a high sensing sensitivity, as compared with thecover window of Comparative Example 2. Also, because the thickness to ofthe cover window 70 of Example 1 has a value from about 150 μm to about700 μm, specifically about 400 μm or less, as described above, the coverwindow 70 may have a sensing sensitivity almost equal to that of thecase in which the cover window of Comparative Example 1 has a thicknessof about 700 μm or more.

As such, because the cover window 70 according to the embodimentincludes the window substrate WS including the polymer resin, the coverwindow 70 has considerable flexibility, and impact and/or scratchresistance. Also, because the cover window 70 includes PVDF having ahigh relative permittivity and the thickness thereof is minimized, thesensing sensitivity of the display apparatus 1 may be sufficientlysecured. Therefore, the cover window 70 capable of improving thereliability of the product may be provided.

According to an embodiment, an adhesive layer 60 may be in contact witha second surface S2 of the window substrate WS. As described above, theadhesive layer 60 may include an OCA. The relative permittivity of theadhesive layer 60 may be greater than the relative permittivity of thewindow substrate WS. For example, the relative permittivity of theadhesive layer 60 may have a value of about 7 or more, or about 8 ormore. Therefore, the sensing sensitivity of the display apparatus 1 maybe improved.

According to an embodiment, a thickness tb of the adhesive layer 60 mayhave a value from about 100 μm to about 300 μm, or from about 150 μm toabout 300 μm. As the thickness t1 of the window substrate WS decreases,the impact resistance of the cover window 70 may decrease. This maycause damage to the display panel (see 10 of FIG. 2 ) due to externalimpact and may increase the possibility of bright spot or dark spotdefects. As described above, the thickness t1 of the window substrate WSmay be minimized to further improve the sensing sensitivity of thedisplay apparatus 1. The above problem may be compensated by increasingthe thickness tb of the adhesive layer 60 as much as the reducedthickness t1 of the window substrate WS. For example, the sum of thethickness t1 of the window substrate WS and the thickness tb of theadhesive layer 60 may have a value from about 200 μm to about 950 μm.This is because, for the same thickness, the degree to which theadhesive layer 60 contributes to the impact resistance of the displayapparatus 1 is greater than the degree to which the window substrate WScontributes to the impact resistance of the display apparatus 1.

FIG. 9 is a schematic cross-sectional view of a cover window and anadhesive layer of a display apparatus according to another embodiment. Adescription of elements that are the same as or corresponding to theelements described above with reference to FIG. 8 are omitted, and thefollowing description will be mainly given focusing on differences.

Referring to FIG. 9 , a hard coating layer HC′ may include a first hardcoating layer HC1 on a first surface S1 of a window substrate WS and asecond hard coating layer HC2 on a second surface S2 opposite to thefirst surface S1 of the window substrate WS. The second hard coatinglayer HC2 may be between the window substrate WS and an adhesive layer60. For example, the adhesive layer 60 may attach the second hardcoating layer HC2 and the optical function layer 50 (see FIG. 2 ).

According to an embodiment, the second hard coating layer HC2 mayinclude polysilsesquioxane or an acrylic polymer material. Also, thesecond hard coating layer HC2 may include a conductive polymer andprevent external static electricity. In an embodiment, the second hardcoating layer HC2 may include a polymer same as or material differentfrom that of the first hard coating layer HC1. According to anembodiment, a thickness t3′ of the second hard coating layer HC2 mayhave a value from about 5 μm to about 20 μm, or from about 5 μm to about10 μm, and may have, specifically, about 5 μm. In an embodiment, thethickness t3′ of the second hard coating layer HC2 may be same as orsmaller than the thickness t2′ of the first hard coating layer HC1.

Even when the second hard coating layer HC2 is provided, a thickness ta′of a cover window 70, that is, the sum of a thickness t1′ of the windowsubstrate WS, a thickness t2′ of the first hard coating layer HC1, andthe thickness t3′ of the second hard coating layer HC2 may have a valuefrom about 150 μm to about 700 μm, from about 150 μm to about 600 μm,from about 150 μm to about 500 μm, from about 150 μm to about 400 μm, orfrom about 150 μm to about 300 μm.

According to the embodiments as described above, the cover window, whichhas considerable flexibility, hardness, and scratch resistance,minimizes the occurrence of cracks due to external impact, and minimizesa decrease in the sensing sensitivity of the input sensing layer, andthe display apparatus including the cover window may be implemented.Therefore, the cover window having improved product reliability and thedisplay apparatus including the cover window may be provided.

Up to this point, only the cover window and the display apparatusincluding the cover window have been mainly described, but thedisclosure is not limited thereto. For example, it will be understoodthat a method of manufacturing such a cover window and a displayapparatus including the cover window also falls within the scope of thedisclosure.

It should be understood that embodiments described herein should beconsidered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each embodimentshould typically be considered as available for other similar featuresor aspects in other embodiments. While one or more embodiments have beendescribed with reference to the figures, it will be understood by thoseof ordinary skill in the art that various changes in form and detailsmay be made therein without departing from the spirit and scope asdefined by the following claims.

What is claimed is:
 1. A cover window comprising: a window substratehaving a first hardness and comprising polyvinylidene fluoride (PVDF);and a hard coating layer on at least one surface of the window substrateand having a second hardness which is greater than that of the windowsubstrate.
 2. The cover window of claim 1, wherein the window substratecomprises a copolymer of a first polymer resin and the PVDF.
 3. Thecover window of claim 2, wherein the first polymer resin comprisespolymethyl methacrylate (PMMA).
 4. The cover window of claim 1, whereina relative permittivity of the window substrate has a value from about 3to about
 6. 5. The cover window of claim 1, wherein a thickness of thewindow substrate has a value from about 100 μm to about 650 μm.
 6. Thecover window of claim 1, wherein the hard coating layer comprises afirst hard coating layer that is on a first surface of the windowsubstrate and has a thickness less than that of the window substrate. 7.The cover window of claim 6, wherein the thickness of the first hardcoating layer has a value from about 10 μm to about 50 μm.
 8. The coverwindow of claim 6, wherein a hardness of the first hard coating layer isgreater than that of the window substrate, and wherein when the hardnessof the first hard coating layer is measured in a pencil hardness, thehardness of the first hard coating layer has a value of at least 7H. 9.The cover window of claim 6, wherein the hard coating layer furthercomprises a second hard coating layer on a second surface opposite tothe first surface of the window substrate.
 10. The cover window of claim9, wherein a thickness of the second hard coating layer has a value fromabout 5 μm to about 20 μm.
 11. The cover window of claim 1, wherein thehard coating layer comprises polysilsesquioxane or an acrylic polymermaterial.
 12. The cover window of claim 1, wherein the sum of athickness of the window substrate and a thickness of the hard coatinglayer has a value from about 150 μm to about 700 μm.